The quickness with which the takeover and bail out of Bear Stearns from JP Morgan Chase and the Federal Reserve has shareholders and Congress wanting answers.

NEW YORK (Reuters) - Stunned Bear Stearns shareholders who saw investments virtually wiped out overnight when a takeover deal with JPMorgan Chase was unveiled are demanding to know how it was put together in the first place.

For instance, they -- and Washington lawmakers -- want answers on how the deal was arranged, and gained government approval and financing, all in a few hours, and seemingly without alternative bidders being canvassed.

They also have a host of questions about the role of the Federal Reserve and the Treasury Department in engineering the emergency deal.

So far, some crucial details remain murky.

"Under the circumstances, shareholders should be entitled to know just about everything," said James Melican, chairman of shareholder advisory firm Proxy Governance Inc, which is expected to make a recommendation to investors on whether or not the deal should be approved.

"There needs to be full disclosure of exactly what happened over the weekend," he said. Investors have "an absolute right to know whether or not there is any other alternative mechanism that could either keep Bear Stearns in business or at least have them get a more appropriate price for their shares."

Billions of dollars in shareholder value has been wiped away in the last week. Based on current market prices, the takeover is valued at $2.41 a share, a shockingly low offer compared with Bear's $159 stock price last April.

Another highly unusual aspect of the deal is the way JPMorgan Chase & Co has been allowed into the Bear Stearns Cos Inc headquarters to provide "management oversight of its operations."

If shareholders were to reject the JPMorgan offer, JPMorgan still would have been in a position to understand everything about Bear's trading strategies, staff quality and assets.

JPMorgan even has an option to buy the Bear Stearns' building if the deal collapses.